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Speed Control Reassemby???

Posted: Sat Jul 11, 2009 1:30 pm
by jesse_27
Hello,

I am in the process of a refurbish on an old machine I came across. When I attempt to replace the speed control bracket it is hitting the control sleave. Is there an adjustment I can make so they do not touch?

Jesse

Posted: Sat Jul 11, 2009 2:41 pm
by billmayo
jesse_27 wrote:Hello,

I am in the process of a refurbish on an old machine I came across. When I attempt to replace the speed control bracket it is hitting the control sleave. Is there an adjustment I can make so they do not touch?

Jesse
YES, it is called the high speed adjustment. You loosen the idler gear nut and screw in the set screw with an allen wrench that the nut is on. I normally set the head of the setscrew even with outside of a thin nut or about 1/3 of the way in on a thick (normal) nut. Use a tach to determine if the high speed is 5000 RPM or higher. If no tach, then I check that the motor belt is even or slighly recessed on the motor sheaves at the FAST position. I find close counts if a new drive belt was installed. After 20-50 hrs, I recheck the high speed adjustment.

As an added note: What I do for my shopsmiths is not recommended by Shopsmith. I back the set screw out quite a ways. I use vise grip plier on the worm control shaft and turn it very very slowly increasing the speed until I hear the control sheave starting to hit the speed control bracket. Then I turn the worn control shaft the other way a 1/4 turn or more to get the speed control handle set screw indention on the worm gear shaft at 12:00 (straight up) for setting the speed control dial at FAST and installing the speed control handle. Turn the set screw in until the it contacts the quadrant and lock the nut on the set screw. I find I can get higher (MAX) RPMs (6000+) using this method on some headstocks but it is not recommended for most people.

Posted: Mon Jul 13, 2009 5:43 pm
by jesse_27
Thanks for the advice. I had adjusted the screw set and that did not solve the problem the Control Sheave kept slipping out towards the speed control assembly. I eventually fixed it by adjusting the speed control assembly before pulling the belt back over the lower stationary sheave. the extra pressure on the mechanisim seemed to hold everything in place much better. Is this potential harmful to the machine? I know I am not to adjust the speed dial while the machine is not running but this was the only way I could get the separation I need to allow for the sheaves to move without metal on metal contact.